CN110402292A

CN110402292A - The cooling device and manufacturing method of rail

Info

Publication number: CN110402292A
Application number: CN201880017677.2A
Authority: CN
Inventors: 奥城贤士; 木岛秀夫; 石川启史
Original assignee: Jitomi Corp
Current assignee: Jitomi Corp; JFE Steel Corp
Priority date: 2017-03-15
Filing date: 2018-03-14
Publication date: 2019-11-01
Also published as: JP6658895B2; CA3056345C; CA3056345A1; AU2018235626B2; EP3597780A1; BR112019018681B8; JPWO2018168969A1; AU2018235626A1; WO2018168969A1; US20210348251A1; EP3597780A4; US11453929B2; BR112019018681B1; BR112019018681A2

Abstract

The cooling device and manufacturing method of a kind of rail of rail that can be manufactured inexpensively high rigidity and high tenacity are provided.A kind of cooling device of rail (2), pressure cooling is carried out to rail (1) by the head (11) from the rail (1) to austenitic temperature region and foot (12) spray cooling medium of, wherein, have: the first cooling end (21), with multiple first cooling manifolds (211a~211c) and the first driving portion (213a~213c), cooling medium of the multiple first cooling manifold (211a~211c) to the crown side Mian Jitou of head (11) injection gas, first driving portion (213a~213c) makes the cooling medium sprayed from the first cooling manifold (211a~211c) and keeping at least one of multiple first cooling manifolds (211a~211c) the first cooling manifold (211a~211c) mobile Throw distance variation；And second cooling end (22), there is the second cooling manifold (221) of the cooling medium to foot (12) injection gas.

Description

The cooling device and manufacturing method of rail

Technical field

The present invention relates to the cooling device of rail and manufacturing methods.

Background technique

As wear resistance and the rail of excellent tenacity, it is known to the high rigidity that head is made of fine pearlitic structrure Rail.Such high rigidity rail is usually manufactured using manufacturing method below.

Firstly, by the rail in the austenitic temperature region after hot rolling or being heated to be the rail in austenitic temperature region with just Vertical state heat treated device is moved in.Upright state refers to the shape that the head of rail becomes top and foot palm part becomes lower section State.At this point, rail is to keep the state of the mill length of such as 100m or so or be cut off (hereinafter also referred to as " sawed-off ".) The state heat treated device for the length that length at each rail is such as 25m or so is carried.It should be noted that in steel In the case that rail is by the sawed-off carrying of heat treated device later, annealing device is divided into corresponding with sawed-off rail sometimes Length multiple sections.

Next, the tiptoe portion of rail is limited by clamping element in annealing device, crown face, the head side, foot of rail Metacarpus, the abdomen being set as desired in turn force cooling by the air as cooling medium.In the manufacture of such rail In method, by micro- to forcing to be integrally formed into the head comprising inside of rail and cooling velocity when cooling controls Thin pearlitic structrure.In the pressure based on annealing device is cooling, in general, carrying out cooling until the temperature on head becomes Until 350 DEG C~650 DEG C or so.

In turn, be forced rail after cooling the limitation based on clamping element be released and be transported to it is cooling bed after, quilt It is cooled to room temperature.

For example, being required for rail high under environment harsh as the natural resources stope of coal or iron ore etc. Wear resistance and high tenacity.However, in the case where the tissue of rail is bainite, wear resistance is reduced, for martensite In the case of, toughness reduces.Therefore, as the tissue of rail, need the tissue of head entirety at least 98% the above are pearlite Tissue.Moreover, the more fine tissue of the sheet gap of pearlite, then wear resistance more improves, therefore in pearlitic structrure It is also required to the miniaturization of sheet gap.

In addition, rail is at most using to wearing 25mm until, therefore is not only head surface, and requirement from a surface to Wear resistance until the inside of the depth of 25mm.

Patent document 1 discloses following method: the temperature on the head of the rail in cooling is forced in measurement, oblique from temperature history Start to make the flow of cooling medium to increase when spending the generation due to the heat of transformation and becoming flat, reinforces cooling, thus make rail Surface and internal hardness rise.

In addition, patent document 2 discloses following method: force cooling the first half to carry out the cooling based on air, it is latter The cooling based on mist is partly carried out, is thus formed as high rigidity until the head center of rail.

Citation

Patent document

Patent document 1: Japanese Unexamined Patent Publication 9-227942 bulletin

Patent document 2: Japanese Unexamined Patent Publication 2014-189880 bulletin

Summary of the invention

Subject to be solved by the invention

However, in method described in Patent Document 1, in order to increase the injection flow of cooling medium and the fortune of air blower Row cost increase, therefore, it is desirable to inhibit to it.

In addition, need to supply water in method described in Patent Document 2 in order to carry out misting cooling, thus run at This raising, or equipment as water supplying tubing or drainage piping is needed, therefore the increase of the cost of initial investment becomes problem. Moreover, cold spot can be generated, therefore cooling velocity locally rises when being cooled to low temperature, it may be to martensite or bainite The tissue that such toughness or wear resistance are remarkably decreased carries out phase transformation.

Therefore, it is made currently invention addresses above-mentioned project, its purpose is to provide one kind can be manufactured inexpensively height The cooling device and manufacturing method of the rail of the rail of hardness and high tenacity.

Solution for solving the problem

A form according to the present invention, provides a kind of cooling device of rail, passes through the rail to austenitic temperature region Head and foot spray cooling medium pressure cooling is carried out to above-mentioned rail, wherein the cooling device of above-mentioned rail has: First cooling end, has multiple first cooling manifolds and the first driving portion, and the multiple first cooling manifold is to above-mentioned head The above-mentioned cooling medium of gas is sprayed in the crown side Mian Jitou, and first driving portion is by making above-mentioned multiple first cooling manifolds At least one of the first cooling manifold it is mobile and make the throw distance variation for the cooling medium sprayed from first cooling manifold； And second cooling end, there is the second cooling manifold that above-mentioned cooling medium is sprayed to above-mentioned foot.

A form according to the present invention, provides a kind of manufacturing method of rail, wherein by austenitic temperature region Rail head and foot's spray cooling medium come when force cooling to above-mentioned rail, from multiple first cooling manifolds to The above-mentioned cooling medium of the crown side the Mian Jitou injection gas on above-mentioned head, from the second cooling manifold in the injection of above-mentioned foot State cooling medium, by make to make and the first cooling manifold of at least one of above-mentioned multiple first cooling manifolds is mobile from this first The throw distance variation of the cooling medium of cooling manifold injection.

Invention effect

A form according to the present invention provides a kind of rail of rail that can be manufactured inexpensively high rigidity and high tenacity Cooling device and manufacturing method.

Detailed description of the invention

Fig. 1 is the length direction diagrammatic cross-section for indicating the cooling device of one embodiment of the present invention.

Fig. 2 is the width direction center diagrammatic cross-section of the cooling device of one embodiment of the present invention.

Fig. 3 is the cross-sectional view for indicating each position of rail.

Fig. 4 is the top view for indicating the peripheral equipment of cooling device.

Specific embodiment

In detailed description below, more spy is recorded in order to provide being understood completely for embodiments of the present invention Fixed detail section.However, can be implemented without above-mentioned specific detail section with more than one embodiment Situation is self-evident.In addition to this, known structure and device are shown with schematic diagram in order to simplify attached drawing.

Firstly, referring to Fig.1~Fig. 4, illustrates the structure of the cooling device 2 of the rail 1 of a form of the invention.Cooling device It is used in 2 heat treatment procedures carried out after aftermentioned hot-rolled process or hot saw break process, the rail 1 of high temperature is forced It is cooling.As shown in figure 3, rail 1 is under orthogonal with the length direction of rail 1 section view observation, by head 11, foot 12, web Portion 13 is constituted.Head 11 and foot 12 are opposite in (up and down direction of Fig. 3) in above-below direction under the section view observation of Fig. 3, in width It is each extended on degree direction (left and right directions of Fig. 3).The width on the head 11 that web portion 13 configures upside in above-below direction The center in direction and the center of the width direction of the foot 12 in downside configuration link, and vertically extend.

As shown in Figure 1, cooling device 2 has the first cooling end 21, the second cooling end 22, a pair of of clamping element 23a, 23b, machine Thermometer 24, trucking department 25, control unit 26 and the rangefinder 27 being set as desired in device.Force cooling rail 1 with Front position is configured at cooling device 2.Front position is the z-axis direction positive direction that head 11 is configured on the upside of as vertical direction Side and foot 12 are configured at the state of the z-axis direction negative direction side on the downside of as vertical direction.It should be noted that in Fig. 1 and In Fig. 4, x-axis direction is head 11 and the width direction that foot 12 extends, and y-axis direction is the length direction of rail 1.Moreover, x Axis, y-axis and z-axis are mutually orthogonal.

The section view observation shown in Fig. 1 of first cooling end 21 is lower with 3 first cooling manifold 211a~211c, 3 the One adjustment section 212a~212c, 3 first driving portion 213a~213c.

The cooling medium ejiction opening and head that 3 first cooling manifold 211a~211c will be configured with a few mm~100mm spacing The crown face (z-axis side end face to the upper side) in portion 11 and head side (both ends of the surface of x-axis direction) are respectively oppositely arranged.That is, In Under section view shown in FIG. 1 observation, the first cooling manifold 211a configuration is in the upside as z-axis positive direction side on head 11, and first Cooling manifold 211b configuration is configured in the left side as negative direction of the x-axis side on head 11, the first cooling manifold 211c on head 11 The right side as positive direction of the x-axis side.Moreover, 3 first cooling manifold 211a~211c are along length direction (the y-axis side of rail 1 To) arrangement and be respectively set multiple.3 first cooling manifold 211a~211c are from cooling medium ejiction opening to the crown on head 11 Face and head side spray cooling medium, thus carry out pressure cooling to head 11.It should be noted that cooling medium uses sky Gas.

3 the first adjustment portion 212a~212c are respectively arranged at each cooling Jie of 3 first cooling manifold 211a~211c Matter feed path.3 the first adjustment portion 212a~212c have the confession for measuring the cooling medium in each cooling medium feed path The flow control valve (not shown) of the supply amount of determination part (not shown) and adjustment cooling medium to amount.Moreover, 3 first tune Whole 212a~212c is electrically connected with control unit 26, and the measurement result of the flow based on determination part is sent to control unit 26. In addition, 3 the first adjustment portion 212a~212c receive to make flow control valve events from the control signal that control unit 26 obtains, adjust The injection flow of the cooling medium of whole injection.That is, the flow for the cooling medium that 3 the first adjustment portion 212a~212c are sprayed Monitoring and adjustment.It should be noted that 3 the first adjustment portion 212a~212c are set in the length direction arrangement along rail 1 It sets and is respectively set on 3 multiple first cooling manifold 211a~211c.

3 first driving portion 213a~213c are to be separately connected and be arranged with 3 first cooling manifold 211a~211c The actuators such as working cylinder or electric motor can be such that the first cooling manifold 211a moves along the z-axis direction, can make the first cooling collection Pipe 211b, 211c are moved along the x-axis direction.3 first driving portion 213a~213c are electrically connected with control unit 26, are received from control unit The 26 control signals obtained, make 3 first cooling manifold 211a~211c along the z-axis direction or x-axis direction is mobile.That is, utilizing 3 First driving portion 213a~213c and 3 first cooling manifold 211a~211c are moved respectively, thus adjust separately 3 it is first cold But the jet face of collector 211a~211c i.e. spray distance of cooling medium at a distance from the crown side Mian Huotou on head 11.Spray Distance is penetrated using each surface of rail 1 and the distance between the jet face of the first cooling manifold 211a~211c opposite with them To define.The adjustment of the spray distance adjusts the x-axis direction position of collector and driving first driving portion 213a~213c Or z-axis direction position carries out.At this point, for example, having clamped the foot 12 of rail 1 using aftermentioned clamping element 23a, 23b In the state of the both ends of left and right directions, first cooling manifold 211a~211c is measured in advance according to each product size of rail Z-axis direction position or x-axis direction position and spray distance relationship.Also, based on about the rail ruler for becoming cooling object The very little relationship sets the z-axis direction position or x-axis direction position of first cooling manifold 211a~211c, and thus, it is possible to obtain The spray distance of target.In addition, after having started the cooling based on cooling device 2, the temperature based on thermometer 24 in machine Measurement result drives first driving portion 213a~213c, makes throw distance variation, and cooling velocity is thus made to become target model It encloses.That is, in the case where cooling velocity is too fast compared with target zone, drive first driving portion 213a~213c and to injection The side adjustment that distance increases, declines cooling velocity.Conversely, in the case where cooling velocity is excessively slow compared with target zone, The side for driving first driving portion 213a~213c and reducing to spray distance adjusts, and accelerates cooling velocity.

In addition, the adjustment of spray distance can also be as shown in Figure 1 or 2, in first cooling manifold 211a~211c, this is each Collector setting measures the rangefinder 27 of the distance on surface of each collector to opposite rail 1, based on 27 pairs of these rangefinders injections The measured value of distance drives first driving portion 213a~213c, to adjust spray distance.In this case, it presets and is based on The measured value of rangefinder 27 controls the device of the driving of first driving portion 213a~213c.Function as the device can be by Control unit 26 is undertaken, and thus sends the signal from rangefinder 27 to control unit 26.Laser displacement can be used in rangefinder 27 The measurement devices such as meter or eddy current type displacement meter.

In the stage carried to cooling device 2 or cooling based on cooling device 2, rail 1 generates up and down sometimes The bending (hereinafter also referred to as " warpage ") in direction (the z-axis direction in Fig. 1) is curved on left and right directions (x-axis direction in Fig. 1) Bent (being also only called " bending ").The warpage or it is curved whether there is or not or degree actual spray distance can be impacted.Moreover, sticking up It is bent or it is curved whether there is or not or degree it is different for becoming each rail of cooled material.Therefore, it is sprayed to further increase The Adjustment precision for penetrating distance, being preferably based on rangefinder 27 makes first driving portion 213a~213c to the measurement result of spray distance Driving, close to the spray distance as target.

In addition, for example, (can also scheme along its length as shown in Figure 2 when enumerating an example of the first cooling manifold 211a Y-axis direction in 2) survey is respectively set in two end sides of length direction (y-axis direction) of multiple first cooling manifold 211a of arrangement Distance meter 27.Rangefinder 27 is set in each first cooling manifold 211a in this way, even if generating warpage and 1 edge of rail in rail 1 Length direction be deformed into it is wavy in the case where, also can be in a manner of the shape along rail, that is, with each first cooling manifold The equidistant mode to rail 1 of 211a adjusts z-axis direction position (the up and down direction position of each first cooling manifold 211a It sets).Thereby, it is possible to carry out the adjustment of the spray distance of each first cooling manifold 211a with avoiding the influence of the warpage of rail 1.It needs Warpage is generated in rail 1 even if being noted that, the variation of the section shape of rail 1 is also more micro- than the amount of warpage in up and down direction It is small, therefore the rangefinder 27 of the first cooling manifold 211a setting can also be substituted in and be based in aftermentioned second cooling manifold The rangefinder 27 of 221 settings drives the first driving portion 213a.

In addition it is also possible to it is same as the first cooling manifold 221a, ranging is also provided with about first cooling manifold 211b, 211c Instrument 27, the measured value based on the rangefinder drive driving portion 213b, 213c.It similarly can be avoided the left and right of rail 1 as a result, Influence of the curved generation to spray distance.

After having started the cooling based on cooling device 2, the temperature measuring based on thermometer 24 in machine is as a result, make One driving portion 213a~213c driving, makes throw distance variation, becomes cooling velocity in target zone or close to mesh Mark range.At this point, the warpage of up and down direction or the curved changed condition of left and right directions, spray distance is due to sticking up in cooling It is bent or it is curved influence and may change.However, even if in this case, also each collection can be measured using rangefinder 27 Pipe and opposite the distance between rail surface, therefore the spray distance associated with the generation of warpage is being changed what addition considered On the basis of, it can correctly set spray distance.

It should be noted that 3 first driving portion 213a~213c be arranged in a row in the length direction along rail 1 it is multiple 3 first cooling manifold 211a~211c be respectively set.

Second cooling end 22 has the second cooling manifold 221, second adjustment portion 222, the second driving portion 223c.

The following table with the cooling medium ejiction opening of a few mm~100mm spacing configuration and foot 12 of second cooling manifold 221 Face (end face on the downside of up and down direction) is oppositely arranged.That is, second cooling manifold 221 is set under section view observation shown in Fig. 1 The downside of foot 12.Moreover, the second cooling manifold 221 be arranged along the length direction of rail 1 it is multiple.Second cooling manifold 221 from cooling medium ejiction opening for the lower surface spray cooling medium of foot 12, pressure cooling thus is carried out to foot 12.It needs It is noted that air can be used in cooling medium.

Second adjustment portion 222 is set to the cooling medium feed path of the second cooling manifold 221.Second adjustment portion 222 has There is the determination part (not shown) of the supply amount of the cooling medium in measurement cooling medium feed path and adjusts the confession of cooling medium To the flow control valve (not shown) of amount.Moreover, second adjustment portion 222 is electrically connected with control unit 26, by determination part to flow Measurement result is sent to control unit 26, receives to make flow control valve events from the control signal that control unit 26 obtains, adjustment spray The injection flow for the cooling medium penetrated.That is, the monitoring and adjustment of the flow for the cooling medium that second adjustment portion 222 is sprayed. It should be noted that the second multiple cooling manifolds 221 is arranged in the length direction arrangement along rail 1 in second adjustment portion 222 It is respectively set.Moreover, in the following description, by first cooling manifold 211a~211c and the second cooling manifold 221 also general name For cooling manifold.

Second driving portion 223 is to be separately connected working cylinder or the electric motor etc. of setting with the second cooling manifold 221 to actuate Device can be such that the second cooling manifold 221 moves along the vertical direction.Second driving portion 223 is electrically connected with control unit 26, is received from control The control signal that portion 26 processed obtains, moves the second cooling manifold 221 along the vertical direction.That is, using the second driving portion 223 and Two cooling manifolds 221 are mobile, thus adjust the distance between the jet face of the second cooling manifold 221 and the lower surface of foot 12 i.e. The spray distance of cooling medium.Spray distance in this is with the lower surface of foot 12 and the opposite with the lower surface second cooling collection The distance between jet face of pipe 221 defines.The adjustment of the spray distance adjusts the and driving the second driving portion 223 The z-axis direction positions of two cooling manifolds 221 carries out.At this point, for example, having clamped steel using aftermentioned clamping element 23a, 23b In the state of the both ends of the left and right directions of the foot 12 of rail 1, in advance measure the second cooling manifold 221 z-axis direction position with The relationship of spray distance.Also, the z-axis direction position of the second collector 221 is set based on the relationship, thus, it is possible to obtain target Spray distance.

Alternatively, can also be as shown in Figure 1 or 2, in the second cooling manifold 221 setting measurement to the second cooling manifold 221 The rangefinder 27 of the distance of the lower surface of opposite foot 12 makes second to the measurement result of spray distance based on the rangefinder 27 Driving portion 223 drives, to adjust spray distance.In this case, the measurement based on rangefinder 27 to spray distance is preset Value controls the device of the driving of the second driving portion 223.Function as the device can be undertaken by control unit 26, thus in the future It is sent from the signal of rangefinder 27 to control unit 26.Rangefinder 27 with it is same the case where being set to first cooling end 211a~211c Sample uses the measurement devices such as laser displacement gauge or eddy current type displacement meter.

The presence or absence of warpage generated in the stage carried to cooling device 2 or cooling based on cooling device 2 is stuck up Bent degree is different for becoming each rail of cooled material.It is therefore, same as first cooling manifold 211a~211c, In order to further increase the Adjustment precision of spray distance, being preferably based on rangefinder 27 makes the second driving to the measured value of spray distance Portion 223 drives.Here, can also be based on not being to be set to the rangefinder 27 of the second cooling manifold 221 but to be set to first cold But the measured value that the rangefinder 27 of collector 211a is adjusted the distance drives the second driving portion 223.

In addition, same as first cooling manifold 211a~211c, as shown in Fig. 2, can also arrange along its length Rangefinder 27 is respectively set in two end sides of the length direction of multiple second cooling manifolds 221.In this way in each second cooling collection Rangefinder 27 is arranged in pipe 221, even if in the case where rail 1 generates warpage and rail 1 is in hummock to deform along its length, Can be in a manner of the shape along rail, that is, by each second cooling manifold 221 to rail 1 it is equidistant in a manner of, adjust The z-axis direction position of whole each second cooling manifold 221.It is cold thereby, it is possible to carry out each second with avoiding the influence of the warpage of rail 1 But the adjustment of the spray distance of collector 221.It should be noted that even if generating warpage in rail 1, the section shape of rail 1 Variation is also more small than the amount of warpage in up and down direction, therefore can also replace the rangefinder 27 for being set to the second cooling manifold 221, The second driving portion 223 is driven based on the rangefinder 27 for being set to the first cooling manifold 211a.

It should be noted that the first multiple coolings are arranged in the length direction arrangement along rail 1 in the second driving portion 223 It is respectively set on collector 221.

In addition, in order to cope with the size of a variety of different rail 1, the first cooling end 21 and the second cooling end according to specification 22 preferably have can with the head 11 and foot 12 relative to rail 1 and cooling manifold become above-mentioned defined position side The mechanism of formula change setting position.

A pair of of clamping element 23a, 23b carry out rail 1 and be the both ends by clamping the left and right directions of foot 12 respectively The device of bearing and limitation.A pair of of clamping element 23a, 23b are set throughout several meters that endlong separate every time of the length direction of rail 1 It sets multiple.

Thermometer 24 is the thermometer for radiating the non-contact types such as thermometer in machine, measures an at least position on head 11 Surface temperature.Thermometer 24 is electrically connected with control unit 26 in machine, by the measurement result of the surface temperature in crown face to control unit 26 send.Moreover, thermometer 24 is in the pressure cooling period for carrying out rail 1 in machine, continuously with the interval of defined time Measure the surface temperature on head.

Trucking department 25 is the handling device connecting with a pair of of clamping element 23a, 23b, by making the edge a pair of of clamping element 23a, 23b The length direction of rail 1 is mobile and rail 1 is carried in cooling device 2.

Measurement result of the control unit 26 based on thermometer 24 in machine adjusts 3 the first adjustment portion 212a~212c, second Whole 222,3 first driving portion 213a~213c and the second driving portion 223 are controlled, and the injection of cooling medium is thus adjusted Distance and injection flow.Control unit 26 adjusts the cooling velocity on head 11 in a manner of becoming the cooling velocity of target as a result,. The spray distance of cooling medium about the progress of control unit 26 and the method for adjustment of injection flow, are described below.

In addition, as shown in figure 4, being equipped with carrying-station 3 on the periphery of cooling device 2 and moving out platform 4.Carrying-station 3 is from hot rolling Process carries the platform of rail 1 to cooling device 2 before process etc..After moving out platform 4 and being heat-treated using cooling device 2 The platform that rail 1 is carried to the subsequent processing of cooling bed or inspection equipment etc..

Next, illustrating the manufacturing method of the rail of present embodiment.In the present embodiment, wear resistance and tough is manufactured The rail 1 of the excellent pearlitic of property.As rail 1, it is, for example, possible to use form the steel constituted by chemical component below. It should be noted that % relevant to chemical component, which is shown, just refers to mass percent as long as no special limitation.

1.05% or less C:0.60% or more and

C (carbon) is to form cementite in pearlitic rail and improve hardness or intensity and improve the weight of wear resistance The element wanted.However, C content, less than 0.60%, their effect is small, therefore C content is preferably 0.60% or more, more excellent It is selected as 0.70% or more.On the other hand, C's is excessive containing will lead to the increase of the carburizing scale of construction, thus while can expect hard The rising of degree or intensity, but otherwise ductility can be made to decline.Moreover, the increase of C content expands the temperature range in the region γ+θ Greatly, the softening of welding heat affected zone can be encouraged.In view of these adverse effects, C content is preferably 1.05% hereinafter, more preferably 0.97% or less.

1.5% or less Si:0.1% or more and

Si (silicon) is added in rail material in order to which deoxidier and pearlitic structrure are strengthened, but content is less than 0.1% If, above-mentioned effect is small.Therefore, the content of Si is preferably 0.1% or more, and more preferably 0.2% or more.On the other hand, Si It is excessive containing decarburization can be promoted, promote the generation of the surface blemish of rail 1.Therefore, Si content be preferably 1.5% hereinafter, More preferably 1.3% or less.

1.5% or less Mn:0.01% or more and

Mn (manganese) has the effect of declining pearlitic transformation temperature and to make pearlite sheet gap fine and close, thus be in order to High rigidity and effective element are maintained until the inside of rail 1, but content, less than 0.01%, effect is small.Therefore, Mn content is preferably 0.01% or more, and more preferably 0.3% or more.On the other hand, in the case that Mn content is more than 1.5%, pearl The equilibrium phase change temperature (TE) of body of light declines, and organizes to be easy to happen martensitic traoformation.Therefore, Mn content is preferably 1.5% Hereinafter, more preferably 1.3% or less.

P:0.035% or less

P (phosphorus) can be such that toughness or ductility declines if content is more than 0.035%.It is therefore preferable that inhibiting P content.Tool For body, P content is preferably 0.035% hereinafter, more preferably 0.025% or less.It should be noted that if in order to strongly subtract Lack P content and carry out special refining etc., then will lead to cost increase when melting.Therefore, P content be preferably 0.001% with On.

S:0.030% or less

S (sulphur) forms the coarse MnS for stretching and making ductility or toughness to decline along rolling direction.It is therefore preferable that inhibiting S Content.Specifically, S content is preferably 0.030% hereinafter, more preferably 0.015% or less.It should be noted that for pole Power reduces S content and the cost increase when meltings such as increase of melting processing time or fluxing agent is significant.Therefore, S content is preferred It is 0.0005% or more.

2.0% or less Cr:0.1% or more and

Cr (chromium) rises equilibrium phase change temperature (TE), facilitates the miniaturization of pearlite sheet gap, makes hardness or strong Degree rises.Moreover, Cr inhibits effective for the generation of decarburized layer and the combined effect with Sb.Therefore, Cr content is preferably 0.1% or more, more preferably 0.2% or more.On the other hand, in the case that Cr content is more than 2.0%, generate welding defect can Energy property increases, and hardenability increases, and can promote the generation of martensite.Therefore, Cr content is preferably 2.0% hereinafter, more preferably It is 1.5% or less.

It should be noted that the total amount of the content of Si and Cr is preferably 2.0% or less.This is because containing in Si and Cr In the case that the total amount of amount is more than 2.0%, the close property of scale is excessively increased, therefore can hinder the removing of scale, may be promoted Into decarburization.

The steel used as rail 1 other than above-mentioned chemical composition, can also also containing 0.5% Sb below, 1 in 1.0% Cu below, 0.5% Ni below, 0.5% Mo below, 0.15% V below and 0.030% Nb below Kind or element of more than two kinds.

Sb:0.5% or less

Sb (antimony) has prevents the decarburization in the heating aobvious in this way when heating using heating furnace to rail steel raw material The effect of work.When especially Sb is added together with Cr, the content of Sb has the effect of reducing decarburized layer for 0.005% or more. Therefore, in the case where containing Sb, Sb content is preferably 0.005% or more, and more preferably 0.01% or more.On the other hand, such as Fruit Sb content is more than 0.5%, then effect is saturated.Therefore, Si content is preferably 0.5% hereinafter, more preferably 0.3% or less.It needs It is noted that even if can also contain 0.001% Sb below sometimes as miscellaneous in the case where energetically avoiding containing Sb Matter.

Cu:1.0% or less

Cu (copper) is the element that can be realized further high rigidity by solution strengthening.Moreover, Cu is for decarburization Inhibit also effective.In the case where expecting the effect and contain Cu, Cu content is preferably 0.01% or more, and more preferably 0.05% More than.On the other hand, in the case where Cu content is more than 1.0%, in continuously casting or embrittlement is easy to produce when rolling and is caused Skin breakage.Therefore, Cu content is preferably 1.0% hereinafter, more preferably 0.6% or less.

Ni:0.5% or less

Ni (nickel) is to improve toughness or ductility and effective element.Moreover, Ni be by with Cu it is compound add And for inhibiting Cu rupture also effective element.Therefore, in the case where adding Cu, it is desirable to add Ni.But it is small in Ni content In the case where 0.01%, it cannot get these effects.Therefore, in the case where expecting these effects and contain Ni, Ni content is excellent It is selected as 0.01% or more, more preferably 0.05% or more.On the other hand, in the case where Ni content is more than 0.5%, hardenability liter Height can promote the generation of martensite.Therefore, Ni content is preferably 0.5% hereinafter, more preferably 0.3% or less.

Mo:0.5% or less

Mo (molybdenum) is element effective for high intensity, but content, less than 0.01%, effect is small.Therefore, In order to make Mo facilitate high intensity, Mo content is preferably 0.01% or more, and more preferably 0.05% or more.On the other hand, In In the case that Mo content is more than 0.5%, hardenability increases and generates martensite, therefore toughness or ductility extremely decline.Therefore, Mo content is preferably 0.5% hereinafter, more preferably 0.3% or less.

V:0.15% or less

V (vanadium) is to form VC or VN etc. and imperceptibly be precipitated into ferrite, is helped by ferritic precipitation strength In the element of high intensity.Moreover, V is also used as the trap site of hydrogen to play a role, the effect for inhibiting delayed fracture can be also expected Fruit.These effects based on V, V content are preferably 0.001% or more in order to obtain, and more preferably 0.005% or more.Another party The rising in face, addition cost of alloy for the saturation of above-mentioned effect more than 0.15% V is very big.Therefore, V contains Amount preferably 0.15% is hereinafter, more preferably 0.12% or less.

Nb:0.030% or less

Nb (niobium) rises the non-recrystallization temperature region of austenite to high temperature side, and processing when rolling is promoted to strain to Austria Importing in family name's body, it is effective to the miniaturization of resulting pearlite colony or block size.Nb is for ductility or tough as a result, Property improve for effective element.These effects generated in order to obtain by Nb, Nb content is preferably 0.001% or more, more excellent It is selected as 0.003% or more.On the other hand, in the case where Nb content is more than 0.030%, in the casting of the steel raw material of the rail such as steel billet In process of setting when making, the crystallization of Nb carbonitride declines spatter property.Therefore, Nb content is preferably 0.030% hereinafter, more Preferably 0.025% or less.

Rest part other than above-mentioned ingredient includes Fe (iron) and inevitable impurity.As inevitably miscellaneous Matter can allow for being mixed into until 0.015% about N (nitrogen), about O (oxygen), can allow for being mixed into until 0.004%, close In H (hydrogen), can allow for being mixed into until 0.0003%.Moreover, inhibiting rolling contact fatigue characteristic caused by the AlN or TiN of hard Decline.Therefore, Al content is preferably 0.001% or less.Moreover, Ti content is preferably 0.002% hereinafter, more preferably 0.001% or less.It should be noted that rail 1 chemical component composition preferably by above-mentioned ingredient and rest part Fe and Inevitable impurity is constituted.

In the manufacturing method of the rail 1 of present embodiment, firstly, by for example steel is become using continuous casting process casting The steel billet of the above-mentioned chemical component composition of the raw material of rail 1 is moved in heating furnace, is heated to becoming 1100 DEG C or more.

Next, the steel billet after heating is rolled into 1 passage or more using split rolling method machine, roughing mill and finishing mill respectively, Finally it is rolled into the rail 1 (hot-rolled process) of shape shown in Fig. 2.At this point, rolling after rail 1 length direction length at Broken as needed by hot saw for 50m~200m or so, becomes the length (hot saw break process) of such as 25m.It should be noted that In the case where the length of the length direction of rail 1 is short, in heat treatment procedure later, when being cooled down, other places is expected The influence for the cooling medium sprayed to the end face of length direction can be generated.Therefore, the length of rail 1 used in heat treatment procedure The length in direction becomes the lower surface (z-axis of upper surface (end face of z-axis negative direction side) to the foot 12 from head 11 of rail 1 The end face of negative direction side) until 3 times or more of height.On the other hand, the length direction of rail 1 used in heat treatment procedure The upper limit of length be set as mill length (the maximum mill length in hot-rolled process).

After hot rolling or rail 1 that hot saw is had no progeny is carried to cooling device 2 by carrying-station 3, by the cooling (heat of cooling device 2 Science and engineering sequence).At this point, the temperature for the rail 1 carried to cooling device 2 is wished for austenitic temperature region.Mine is used or detour area Between with used rail need become high rigidity, it is therefore desirable to make its rapid cooling using cooling device 2 after rolling.This is Because being formed as the tissue of high rigidity and keeping the sheet gap of pearlite fine, by improving the degree of supercooling in phase transformation, that is, By improving the cooling velocity in phase transformation, the tissue of such high rigidity can be obtained.However, in carrying out cooling device 2 If the tissue of rail 1 is undergone phase transition before cooling, become nature let cool in extremely slow cooling velocity under phase transformation, therefore It is unable to get the tissue of high rigidity.Therefore, when beginning to cool using cooling device 2, become Ovshinsky body temperature in the temperature of rail 1 It spends in the situation below of region, preferably carries out heat treatment procedure after rail 1 is again heated to austenitic temperature region.

On the other hand, when being begun to cool using cooling device 2, in the feelings that the temperature of rail 1 is austenitic temperature region Under condition, do not need to be reheated.

In heat treatment procedure, after rail 1 is transported to cooling device 2, rail is limited using clamping element 23a, 23b 1 foot 12.Then, from 221 spray cooling medium of 3 first cooling manifold 211a~211c and the second cooling manifold, thus By 1 rapid cooling of rail.At this point, the cooling velocity in heat treatment preferably changes according to desired hardness, in addition, if mistake Degree ground promotes cooling velocity, then generates martensitic traoformation, damage toughness sometimes.Therefore, control unit 26 is according to the machine in cooling The temperature-measuring results of thermometer 24 calculate cooling velocity in device, according to the cold of getable cooling velocity and preset target But speed, to adjust the spray distance and injection flow of cooling medium.

Specifically, control unit 26 is in the case where the cooling velocity of calculating is low relative to the cooling velocity of target with cold But the mode that the spray distance of medium is short and the injection flow of cooling medium increases control 3 the first adjustment portion 212a~212c, 222,3, second adjustment portion, first driving portion 213a~213c and the second driving portion 223.On the other hand, in the cooling speed of calculating Spend cooling velocity relative to target it is low in the case where, control unit 26 is with the spray distance of cooling medium is long and the spray of cooling medium The mode of amount of jet reduction control 3 the first adjustment portion 212a~212c, the first driving portion 213a of 222,3, second adjustment portion~ 213c and the second driving portion 223.At this time, if it is desired, control unit 26 can also stop the injection of cooling medium, carry out based on certainly The cooling so let cool.

In addition, the spray distance of cooling medium and the adjustment of injection flow can adjust spray distance and injection stream simultaneously Amount, can also preferentially adjust spray distance.In addition, in order to make control be easy, can also with presumptive temperature history etc. and incite somebody to action Heat treatment procedure is divided into multiple stages (cooling step), in each stage in, will be in the spray distance and injection flow of cooling medium A side be set as constant.Also, it, can also basis about the spray distance or injection flow for being not set to constant another party By the measurement result and getable cooling velocity of thermometer 24 in machine, adjusted in a manner of becoming the cooling velocity of target It is whole.It should be noted that the adjustment based on the cooling velocity of the measurement result of thermometer 24 in machine carried out by control unit 26 According to the measuring interval of thermometer 24 in machine or each stage of heat treatment procedure etc., carried out with the interval of arbitrary time.

It should be noted that becoming in the case where gap, that is, spray distance of cooling manifold and rail 1 is too short in rail 1 When shape, cooling manifold is contacted with rail 1, becomes the reason of equipment breakage.Therefore, spray distance is preferably set to 5mm or more.It is another Aspect, in the case where spray distance is too long, due to the speed of the air of injection subtract decline and become with let cool naturally it is same cold But ability.As previously mentioned, hardness is impaired, therefore the upper limit of spray distance is preferably set to if cooling velocity is remarkably decreased 200mm, but can also not have to be particularly limited to.It should be noted that if utilizing 3 first driving portion 213a~213c and Two driving portions 223 increase the moving distance of each cooling manifold, then need to extend the stroke of working cylinder, therefore the equipment at initial stage is thrown Cost is provided to increase.Therefore, from the viewpoint of equipment investment cost, the upper limit of spray distance can also be set.

Here, in the cooling based on the first cooling end 21, due to by the tissue on the head 11 of rail 1 be set as high rigidity and The fine pearlitic structrure of excellent tenacity, thus it is mainly that head 11 is cooling.On the other hand, based on the second cooling end 22 In cooling, the warpage up and down of the overall length of the rail 1 generated to inhibit the temperature difference due to head 11 and foot 12 is (up and down Bending on direction), it is mainly that foot 12 is cooling.It can control the equalized temperature on head 11 Yu foot 12 as a result,.Wanting to make steel In the case that the hardness on the head 11 of rail 1 rises, need to improve the cooling velocity (amount of cooling water) on head 11, therefore make to be set to 3 First cooling manifold 211a~211c of at least one of first cooling manifold 211a~211c at position or more is mobile and contracts The case where short spray distance, is effective.Moreover, in the case where improving the cooling velocity on head 11, in order to inhibit warpage up and down, foot The cooling velocity in portion 12 is also required to higher.In this case, the case where making the second cooling manifold 221 mobile and shortening spray distance Effectively.That is, it is preferred that according to as target tissue or purposes etc. select the cooling manifold for making throw distance variation.

In addition, needing be heat-treated as previously mentioned, be formed as the tissue of high rigidity to generate phase transformation in heat treatment In it is near want as high rigidity depth until phase transformation complete.Depth needed for the tissue of high rigidity is according to use when using It suitably sets on the way.Also, the surface on head 11 carries out cooling until depth phase needed at least becoming the tissue with high rigidity Until corresponding temperature.For example, needing the feelings of the tissue of the high rigidity of HB330~390 or so in the depth from a surface to 15mm Under condition, the surface temperature on head 11 is 550 DEG C hereinafter, needing the group of the high rigidity of HB390 or more until the depth of 15mm In the case where knitting, the cooling surface temperature until head 11 is carried out as until 500 DEG C or less.Moreover, from a surface to In the case where the tissue for needing the high rigidity of HB330~390 or so until the depth of 25mm, the surface temperature on head 11 is 450 DEG C hereinafter, from a surface to 25mm depth until need the tissue of high rigidity of HB390 or more in the case where, need to carry out Until the cooling surface temperature until head 11 becomes 445 DEG C or less.

After heat treatment procedure, rail 1 by move out platform 4 be carried to it is cooling bed, cooling bed place be cooled to room temperature~ 200℃.Also, after receiving inspection, dispatched from the factory.In inspection, Vickers hardness test or Brinell hardness test are carried out.

Under the harsh environment as the natural resources stope of coal or iron ore etc., high abrasion is required for rail 1 Damage property and high tenacity.Therefore, the rail 1 used under such circumstances preferably do not make wear resistance decline bainite structure or Make the martensitic structure of the damaging decline of endurance, and preferably 98% or more pearlitic structrure.Moreover, keeping sheet gap micro- It refines and the pearlitic structrure of high rigidity can improve wear resistance.It is wanted not only for the surface on the head 11 after rigid manufacture Wear resistance is sought, and wear resistance is also required for the surface after abrasion.The replacement benchmark of rail 1 according to railroad and Difference, but at most using until 25mm depth, thus from a surface to maximum 25mm depth until require as defined in hardness.It is special It is not in detour section, train applies rail 1 big power by centrifugal force, is prone to wear.In detour section, The hardness on the surface on the head 11 of rail 1 is set as HB420 or more, the hardness of the depth used is set as HB390 or more, thus It can be realized long lifetime.

More than, the present invention is illustrated referring to specific embodiment, but is not intended to limit by these explanations Invention.By referring to explanation of the invention, those skilled in the art can also together with the various modifications example of disclosed embodiment Know other embodiments of the invention.Therefore, claims are interpreted as also including that the scope of the present invention and purport are wrapped These variations or embodiment contained.

For example, in the above-described embodiment, by adjusting the spray distance and injection of the cooling medium sprayed to head 11 Flow controls the adjustment of the cooling velocity on head 11, but the present invention is not limited to above-mentioned example.For example, head 11 is cold But the adjustment of speed can also only be adjusted and keeping the injection flow for the cooling medium sprayed to head 11 constant to head 11 The spray distance of the cooling medium of injection carries out.In this case, control unit 26 is according to the measurement knot of thermometer 24 in machine Fruit controls 3 first driving portion 213a~213c and the second driving portion 223, controls spray distance, thus into The adjustment of row cooling velocity.In such a configuration, injection flow is constant, and its control becomes easy, therefore can simplify The structure of one cooling end 21 and the second cooling end 22.

In addition, in the above-described embodiment, 3 first drivings are respectively set in 3 first cooling manifold 211a~211c Portion 213a~213c, but the present invention is not limited to above-mentioned example.As described above, as long as 3 first coolings can be adjusted The spray distance of cooling medium in the first cooling manifold of at least one of collector 211a~211c.It therefore, can be with It is set as to make the more than one cooling manifold equipped with the first driving portion in 3 first cooling manifold 211a~211c mobile Structure, also can be set to can make first whole cooling manifold 211a~211c to one party using first driving portion To mobile structure.

In addition, in the above-described embodiment, being adjusted according to the variation of the cooling velocity on head 11 to the injection of foot 12 Thus the spray distance and injection flow of cooling medium control the adjustment of the cooling velocity of foot 12, but the present invention does not limit It is set to above-mentioned example.For example, the adjustment of the cooling velocity of foot 12 can also be by only adjusting the cooling sprayed to foot 12 The spray distance of medium and a side in injection flow carry out.Moreover, if by the head 11 of rail 1 and the cooling of foot 12 There is no problem for the warpage up and down that the difference of speed generates, then does not have to the spray distance and spray that carry out the cooling medium sprayed to foot 12 The adjustment of amount of jet, the pressure that can also carry out foot 12 by constant spray distance and injection flow are cooling.

In addition, in the above-described embodiment, showing specific chemical component composition as an example, but the present invention does not have Have and is limited to above-mentioned example.The chemical component of the steel used is formed according to usage or the characteristic of needs, also can be used Chemical component composition other than the above.

In addition, in the above-described embodiment, the spray of cooling medium is controlled based on the measurement result of thermometer 24 in machine Distance and injection flow are penetrated, but the present invention is not limited to above-mentioned example.For example, according to the rail 1 of heat treatment procedure The numeric value analysis of surface temperature or temperature change, past real result etc. can estimate the temperature change in heat treatment procedure In the case of, the spray distance and injection flow of cooling medium can also be preset, according to the temperature change estimated to set Fixed value changes spray distance and injection flow.

In addition, in the above-described embodiment, in the section orthogonal to the longitudinal direction of rail 1, being arranged in cooling device 2 3 first cooling manifold 211a~211c, but the present invention is not limited to above-mentioned example.Rail 1 and length direction In orthogonal section, as long as the setting of the first cooling manifold is multiple, the number of setting is not particularly limited.

In addition, in the above-described embodiment, cooling medium has used air, but the present invention is not limited to above-mentioned example Son.As long as the cooling medium used is gas, or N₂Or Ar etc. is other at being grouped as.

(1) cooling device 2 of the rail 1 of a form of the invention is the head by the rail 1 to austenitic temperature region Portion 11 and 12 spray cooling medium of foot and the cooling device 2 for force to rail 1 cooling rail, have: first is cooling Portion 21, multiple first cooling manifold 211a with the cooling medium to the crown side Mian Jitou on head 11 injection gas~ 211c, and keeping the first cooling manifold of at least one of multiple first cooling manifold 211a~211c 211a~211c mobile Make first driving portion 213a~213c of the throw distance variation from first cooling manifold 211a~211c cooling medium sprayed； And second cooling end 22, there is the second cooling manifold 221 of the cooling medium that gas is sprayed to foot 12.

According to the structure of above-mentioned (1), by adjusting cooling medium spray distance and cooling velocity can be controlled, therefore with Such as only compared by the method for the injection flow of cooling medium adjusted to control cooling velocity, cooling medium can be reduced Usage amount, therefore can more be manufactured inexpensively rail 1.Moreover, because cooling medium be gas, therefore with such as patent document 2 The method for switching cooling medium like that and carrying out misting cooling is compared, and is not needed using water, can be simplified equipment, therefore can be more It is manufactured inexpensively rail 1.In addition, even if there is no a possibility that generating cold spot, therefore can at least incite somebody to action when being cooled to low temperature yet The 98% of the tissue on head 11 formed above is fine pearlitic structrure, can be improved toughness, hardness, wear resistance.

(2) it in the structure of above-mentioned (1), is also equipped with through first driving portion 213a~213c of control and adjusts spray distance Control unit 26 and measurement rail 1 surface temperature machine in thermometer 24, control unit 26 is according to by thermometer 24 in machine The getable cooling velocity of measurement result and preset target cooling velocity, to adjust spray distance.

It, can be according to the real result of cooling velocity, to become the most suitable temperature as target according to the structure of above-mentioned (2) The mode of degree resume carries out pressure cooling to rail 1.

(3) in the structure of above-mentioned (1) or (2), the first cooling end, which is also equipped with, to be made from the injection of multiple first cooling manifolds The first adjustment portion of the injection flow variation of cooling medium.

Here, in the case where such as patent document 1 only adjusts method of the injection flow to control cooling velocity like that, only Be injection flow increase if, there are limits for the rising of cooling velocity.Therefore, as patent document 1 manufacturing method In the case of, for example, even if the rail for the requirement high abrasion resistance to be suitable for using in the detour section in mine, it is also difficult to will The quality that high internal hardnessization extremely requires.

In contrast, since spray distance and injection flow can be adjusted, passing through contracting according to the structure of above-mentioned (3) Short spray distance simultaneously increases injection flow, can further increase cooling velocity.Therefore, compared with the method for patent document 1, energy It is enough to improve hardness or wear resistance until the inside on head 11.

(4) in any structure of above-mentioned (1)~(3), the second cooling end also has by keeping the second cooling manifold mobile And make the second driving portion of the throw distance variation for the cooling medium sprayed from the second cooling manifold.

According to the structure of above-mentioned (4), appropriateization of the cooling balance of head 11 and foot 12 can be realized, therefore can press down Make the warpage up and down generated in forcing cooling process.

(5) in any structure of above-mentioned (1)~(4), first cooling manifold 211a~211c, the second cooling manifold 221 Any of the above rangefinder 27 having for measuring spray distance, and have and controlled based on the value that rangefinder 27 is measured to Make the device of any of first driving portion 213a~213c, second driving portion 223 or more.

According to the structure of above-mentioned (5), even if the case where generating warpage in the case where rail 1 generates warpage or in cooling Under, spray distance also can be accurately adjusted, accurately rail 1 can be cooled down.It should be noted that based on by surveying The value that distance meter 27 is measured to adjust the driving portion of position can be for first driving portion 213a~213c, in the second driving portion 223 Either one or two of, or more than one.As long as considering the variation of the spray distance associated with the warpage of rail 1 or bending to cold But it is influenced caused by speed, about the driving portion that the cooling manifold to become larger on the influence is driven, the survey based on rangefinder 27 Definite value carries out the control of driving portion.

(6) manufacturing method of the rail 1 of a form of the invention is on the head by the rail to austenitic temperature region And foot's spray cooling medium and when force cooling to rail, from multiple first cooling manifolds to the crown face on head and head The cooling medium of gas is sprayed in side, from the second cooling manifold to the cooling medium of foot's injection gas, makes multiple first coolings The first cooling manifold of at least one of collector is mobile, thus makes the spray distance for the cooling medium sprayed from the first cooling manifold Variation.

According to the structure of above-mentioned (6), can obtain and above-mentioned (1) same effect.

Embodiment 1

Next, illustrating the embodiment 1 that inventors carry out.It is and upper as conventional example 1 firstly, before embodiment 1 Embodiment difference is stated, to force the condition for not changing spray distance in cooling to manufacture rail 1, is commented about its material Valence.

In conventional example 1, firstly, having cast the A of condition shown in table 1~condition D chemical component using continuous casting process The steel billet of composition.It should be noted that the rest part that the chemical component of steel billet forms is essentially Fe, specifically, being Fe And inevitable impurity.Moreover, 0.001% or less situation is Sb as inevitably miscellaneous about the Sb content in table 1 Matter and the case where be mixed into.It is all the case where being mixed into as inevitable impurity about the content of Ti and Al in table 1.

[table 1]

Next, being reheated the steel billet after casting at after 1100 DEG C or more using heating furnace, extracted out from heating furnace.And And so that section shape becomes final shape (AREMA (The American Railway Engineering and Maintenance-of-Way Association: american railway engineering and road upkeep association) specification 141 pounds of rail) The mode of rail 1 has carried out hot rolling using split rolling method machine, roughing mill and finishing mill.It should be noted that in hot rolling, rail 1 is rolled under the handstand posture that head 11 and foot 12 connect with carrying platform.

In turn, the rail 1 after hot rolling is carried to cooling device 2, (heat treatment procedure) is cooled down to rail 1.This When, rail 1 is rolled with handstand posture in hot rolling, therefore is formed when moving in rail 1 to cooling device 2 by rotation Foot 12 becomes on the downside of vertical direction and head 11 becomes the front position shown in Fig. 3 on the upside of vertical direction, utilizes clamping element 23a, 23b limit foot 12.Also, it is cooled down from cooling manifold injection air as cooling medium.Moreover, Distance, that is, spray distance between cooling manifold~rail is set as 20mm or 50mm and constant, is not changed during cooling.At this point, According to clamping element 23a, 24a, first cooling manifold 211a~211c, rail product size and measure and determine in advance opposite position It sets, drives first driving portion 213a~213c, thus set spray distance.In addition, as patent document 1 cooling means that Sample increases the injection flow of cooling medium from when cooling midway produces the decline for the cooling velocity generated heat based on phase transformation, Maintain the control of cooling velocity.At this point, the temperature for continuously being carried out head 11 using thermometer 24 in machine on one side is surveyed It is fixed, it is carried out in such a way that the temperature according to real result becomes constant cooling velocity using adjustment section 212a~212c on one side The adjustment of injection flow.Also, the cooling surface temperature until head 11 is carried out as until 430 DEG C or less.

After heat treatment procedure, rail 1 is taken out from cooling device 2 to platform 4 is moved out, to cooling bed carrying, utilization is cold But bed carries out the cooling surface temperature until rail 1 as until 50 DEG C.

Then, it is corrected using gaugger, has manufactured the rail 1 as final product.

In addition, sample is chosen and cold saw is disconnected by carrying out to manufactured rail 1, about selected in conventional example 1 Sample has carried out Determination of Hardness.As the method for Determination of Hardness, the width direction center on the head 11 away from rail 1 surface with And the surface on head 11 is to have carried out Brinell hardness test at the position of 5mm, 10mm, 15mm, 20mm and 25mm depth.Table 2 shows The condition of the ingredient in conventional example 1, the setting value of spray distance, the real result value of cooling velocity and the survey of Brinell hardness are gone out Definite value.Moreover, after having carried out the etching based on nital, having been carried out based on optics about selected each sample Microscopical structure observation.

[table 2]

Next, inventors have attempted not to be to control the injection flow of cooling medium but pass through control as embodiment 1 Spray distance processed is come the case where adjusting the cooling velocity in pressure cooling.

In embodiment 1, firstly, having cast the A of condition shown in table 1~condition D chemical component using continuous casting process The steel billet of composition.It should be noted that the rest part that the chemical component of steel billet forms is essentially Fe, specifically, being Fe And inevitable impurity.

Next, it is same as conventional example 1, after being 1100 DEG C or more by the steel billet reheating after casting using heating furnace, Hot rolling has been carried out with handstand posture.

In turn, the rail 1 after hot rolling is carried to cooling device 2, (heat treatment procedure) is cooled down to rail 1.This When, it is same as conventional example 1, it rotates rail 1 when moving in cooling device 2, in the state of becoming front position, utilizes folder Tight part 23a, 23b limit the foot 12 of rail 1.Then, it is carried out from cooling manifold injection air as cooling medium Cooling.Moreover, phase transformation start before the cooling the first half of pressure in cooling manifold~rail between distance i.e. jet length It is constant from 20mm or 50mm is set as.At this point, according to the production of clamping element 23a, 24a, the first cooling manifold 211a~211c, rail Product size and measure and determine relative position in advance, make first driving portion 213a~213c drive, thus set spray distance. In addition, making the first cooling manifold 211a compared with when producing the decline of cooling velocity caused by phase transformation is generated heat in cooling midway The spray distance of~211c is respectively 15mm from 20mm variation, is 45mm from 50mm variation, has carried out the control for maintaining cooling velocity System.Also, the cooling surface temperature until head 11 is carried out as until 430 DEG C or less.

It is same as conventional example 1 after heat treatment procedure, the cooling surface temperature up to rail 1 is carried out using cooling bed It until as 50 DEG C, is corrected using gaugger, thus produces the rail 1 as final product.

In addition, it is same as conventional example 1, sample is chosen by the way that the progress cold saw of the rail manufactured 1 breaks, about selected Sample carried out Determination of Hardness.Table 3 shows the condition of the ingredient in embodiment 1, the setting value of spray distance, cooling velocity The measured value of real result value and Brinell hardness.Moreover, about selected each sample, it is same as conventional example 1, it is based on The structure observation of optical microscopy.

[table 3]

As shown in table 3, in embodiment 1, with ingredient, spray distance and the different embodiment 1-1~1-7 of cooling velocity this 7 conditions carry out the manufacture of rail 1, determine the Brinell hardness on head 11.It should be noted that in embodiment 1-1~1-7 In, it is forcing not making the second cooling manifold 221 mobile in cooling, is keeping 3 first cooling manifold 211a~211c mobile and carry out Force cooling.In embodiment 1-8, do not make the second cooling manifold 221 and 2 first cooling manifolds 211b, 222c mobile, only Keep the first cooling manifold 211a mobile and has carried out forcing cooling.In embodiment 1-9, make 3 the first cooling manifold 211a~ Cooling manifold of this whole of 211c and the second cooling manifold 221 is mobile and has carried out forcing cooling.At this point, according to clamping element 23a, 24a, first cooling manifold 211a~211c, rail product size and measure and determine relative position in advance, make the first driving Portion 213a~213c driving, thus makes throw distance variation.Moreover, embodiment 1-1~1-7 be with it is existing come example 1-1~1-7 Identical cooling velocity has carried out forcing cooling example respectively, with the injection flow of cooling medium in conventional example 1-1~1-7 Cooling velocity is had adjusted, in contrast, adjusting cooling velocity in embodiment 1-1~1-7 with the spray distance of cooling medium.

As shown in table 2 and table 3, in embodiment 1-1~1-7, the surface on head 11 and the depth to 25mm can The case where conventional example 1-1~1-7 that confirming becomes the same terms with cooling velocity distinguishes same hardness.Moreover, existing In example 1-1~1-7, after the fever based on phase transformation, increase the injection flow of cooling medium, therefore is forcing to use in cooling Cooling medium usage amount increase.On the other hand, in embodiment 1-1~1-7, increase the injection flow of cooling medium Add, only adjust cooling velocity and enabling the throw distance variation of cooling medium, therefore compared with conventional example 1-1~1-7, It can reduce in the usage amount for forcing cooling medium used in cooling, cost of energy can be reduced.

In addition, forcing only to make to move to the first cooling manifold 211a of the crown face spray cooling medium on head 11 in cooling In dynamic embodiment 1-8, it is able to confirm that compared with the embodiment 1-1 manufactured with identical component and identical cooling velocity, The hardness of surface and 5mm depth rises the case where HB5 or so.

In addition, confirming the case where every 100m of rail 1 produced generates the lower warpage of 500mm in embodiment 1-1. In contrast, forcing to make the second cooling manifold 221 mobile in cooling and be adjusted in a manner of keeping the amount of cooling water of foot 12 increased In the embodiment 1-9 of spray distance, appropriateization of the cooling balance of head 11 and foot 12 is realized, compared with embodiment 1-1 Warpage is reduced to 1/10, and every 100m becomes the lower warpage of 50mm.

In addition, when having carried out the structure observation of the sample cross-section of conventional example 1-1~1-7 and embodiment 1-1~1-9, confirmation The case where 1 entirety of rail to the surface for including head 11 becomes pearlitic structrure, does not observe martensitic structure or bainite Tissue.

Embodiment 2

Next, illustrating the embodiment 2 that the present inventors carry out.In example 2, one in the same manner as above embodiment While the cooling velocity of cooling medium and cooling flow variation is made to carry out pressure cooling on one side, evaluated about its material.

Firstly, as conventional example 2, as described in Patent Document 2, not changing spray distance before embodiment 2 and carrying out Force cooling midway make cooling medium from air to mist variation carry out cooling method and force cooling midway by changing Become the injection pressure of cooling medium and changes cooling flow to carry out cooling method.In conventional example 2, firstly, using connecting Continuous casting has cast the steel billet of the composition of the chemical component of condition D and condition F shown in table 1.It should be noted that the change of steel billet Studying the rest part being grouped as is essentially Fe, specifically, being Fe and inevitable impurity.

In turn, the rail 1 after hot rolling is carried to cooling device 2, (heat treatment procedure) is cooled down to rail 1.This When, it is same as conventional example 1, it rotates rail 1 when moving in cooling device 2, with the state of front position, utilizes clamping element 23a, 23b limit the foot 12 of rail 1.Then, air or mist is sprayed as cooling medium from cooling manifold to have carried out cold But.Moreover, distance, that is, spray distance between cooling manifold~rail is set as 20mm or 30mm and constant, do not change in cooling. In addition, in conventional example 2, by heat treatment procedure be divided into the different initial stage cooling step of cooling condition and final cooling step this 2 A stage carries out the cooling surface temperature until head 11 as until 430 DEG C or less.

In addition, it is same as conventional example 1, sample is chosen and cold saw is disconnected by carrying out to manufactured rail 1, about selected Sample carried out Determination of Hardness.Table 4 shows the condition of conventional example 2 and the ingredient in aftermentioned embodiment 2, each cooling step In cooling condition (the real result value of cooling time (only initial stage cooling step), the setting value of spray distance and cooling velocity) And the measured value of Brinell hardness.Moreover, about selected each sample, it is same as conventional example 1, it has carried out based on optical microscopy Structure observation.

[table 4]

As shown in table 4, in conventional example 2, with this 2 conditions of different conventional example 2-1,2-2 of ingredient and cooling condition into The manufacture of rail 1 is gone.It is cooling to be situated between in the first cooling step after forcing cooling start in the case where conventional example 2-1 Matter is cooled down using air, and after it have passed through 20 seconds, in final cooling step, cooling medium is switched to mist from air And cooling in 150 seconds is carried out.Moreover, in the case where conventional example 2-2, after forcing cooling start, cooling step in the early stage And it in final cooling step, all uses air as cooling medium and is cooled down.In addition, in conventional example 2-2, it is cold in the early stage But in step from force it is cooling until by 30 seconds during, the injection pressure of cooling medium is set as 5kPa, then, Using the second cooling step, until by 150 seconds during, the injection pressure of cooling medium is set as 100kPa and is carried out Force cooling.

In conventional example 2-2, in final cooling step along with injection pressure increase and injection flow also increases.And And in conventional example 2-2, the target of the cooling velocity of final cooling step is determined as 15 DEG C/sec, although but determines that with High pressure as 100kPa (high flow capacity) jetted cooling medium, but the real result of cooling velocity becomes 12 DEG C/sec, does not reach To target cooling velocity the case where.

In addition, the sample about conventional example 2-1, when having carried out structure observation, confirms the entirety of the rail 1 comprising surface The case where as pearlitic structrure.In contrast, a part on surface observed martensitic structure in conventional example 2-2 Or the tissue for deteriorating toughness or wear resistance as bainite structure.This consideration be due to misting cooling and water droplet repeatedly compared with The case where position mostly contacted is quenched, and the referred to as region of cold spot is generated is caused.

Next, same as above embodiment, the present inventors make the spray distance of cooling medium as embodiment 2 And injection flow changes and has carried out the manufacture of rail 1.

In example 2, firstly, having cast the A of condition shown in table 1~condition G chemical component using continuous casting process The steel billet of composition.It should be noted that the rest part that the chemical component of steel billet forms is essentially Fe, specifically, being Fe And inevitable impurity.

Next, same as conventional example 1, being reheated the steel billet of casting using heating furnace is 1100 DEG C or more, later, with Handstand posture has carried out hot rolling.

In turn, the rail 1 after hot rolling is carried to cooling device 2, (heat treatment procedure) is cooled down to rail 1.This When, it is same as conventional example 1, it rotates rail 1 when moving in cooling device 2, with the state of front position, utilizes clamping element 23a, 23b limit the foot 12 of rail 1.Also, it is cooled down from cooling manifold injection air as cooling medium.

In addition, in example 2, heat treatment procedure is divided into spray distance and the different initial stage cooling step of cooling velocity With this 2 stages of final cooling step or this 3 stages of initial stage cooling step, cooling during rolling step and final cooling step, The cooling surface temperature until final head 11 is carried out as until 430 DEG C or less.At this point, with according to thermometer 24 in machine The mode that measurement result and getable cooling velocity become the cooling velocity of target control from the first cooling manifold 211a~ The injection flow of the cooling medium of 211c injection.It should be noted that cooling velocity said here is according to each cooling step Beginning and at the end of surface temperature and time for spending of each cooling step and the value that calculates is (average cold in each cooling step But speed), it sometimes also include heating caused by the phase transformation fever generated in each cooling step.

In addition, it is same as conventional example 1, sample is chosen and cold saw is disconnected by carrying out to manufactured rail 1, about selected Sample carried out Determination of Hardness.Moreover, about selected each sample, it is same as conventional example 1, it has carried out based on optical microphotograph The structure observation of mirror.

As shown in table 4, in example 2, with this 9 conditions of the different embodiment 2-1~2-9 of ingredient and cooling condition into The manufacture of rail 1 is gone.As shown in table 4, in embodiment 2-1,2-3,2-4,2-6~2-9 condition, by heat treatment procedure point It is carried out for initial stage cooling step and this 2 stages of final cooling step.Moreover, in the condition of embodiment 2-2,2-5, at heat Science and engineering sequence is divided into this 3 stages progress of initial stage cooling step, cooling during rolling step and final cooling step.

Structure observation in embodiment 2 as a result, in this whole condition of embodiment 2-1~2-9, confirm and include The case where whole tissues on the head 11 on surface become pearlitic structrure.That is, becoming first with conventional example 2-2 in cooling condition In the identical embodiment 2-3 of cooling condition in phase cooling step and final cooling step, also it is able to confirm that comprising surface Whole tissues on head 11 become pearlitic structrure, the case where without martensitic structure or bainite structure.Moreover, implementing In example 2-3, it is able to confirm that the hardness at the position of the ratio 5mm depth other than the surface on head 11 becomes and conventional example 2-1 Roughly the same situation.In contrast, changing the injection flow (injection pressure) of cooling medium simultaneously not changing spray distance It is close with cooling condition in the embodiment 2-2 for realizing the rising of the cooling velocity of the cooling later half in heat treatment procedure Embodiment 2-3 is compared, and is confirmed especially than the hardness decline at the position of 10mm depth.

In addition, the rail 1 produced with the condition of embodiment 2-1,2-2 is confirmed and reaches following condition: as can fit For the condition in detour section and the hardness on surface is HB420 or more, the hardness of 25mm depth is the such item of HB390 or more Part.

Embodiment 3

Next, illustrating the embodiment 3 that the present inventors carry out.In embodiment 3, one in the same manner as above embodiment While changing the cooling velocity of cooling medium, pressure cooling is carried out on one side, and the determining method about spray distance is to the shadow of material Sound is evaluated.

In embodiment 3, firstly, having cast the steel of the chemical component composition of condition D shown in table 1 using continuous casting process Base.It should be noted that the rest part that the chemical component of steel billet forms is essentially Fe, specifically, for Fe and can not keep away The impurity exempted from.

Next, after being 1100 DEG C or more by the steel billet reheating after casting using heating furnace, with the progress of handstand posture Hot rolling.

In turn, the rail 1 after hot rolling is carried to cooling device 2, (heat treatment procedure) is cooled down to rail 1.This When, it rotates rail 1 when moving in cooling device 2, with the state of front position, limits steel using clamping element 23a, 23b The foot 12 of rail 1.The condition of heat treatment procedure is set as the embodiment 2-1 of the record of table 4, also, makees from cooling manifold injection air It is cooled down for cooling medium.

By heat treatment procedure be divided into spray distance and the different initial stage cooling step of cooling velocity and final cooling step this 2 A stage carries out the cooling surface temperature until final head 11 as until 430 DEG C or less.At this point, with according to warm in machine Degree counts 24 measurement result and getable cooling velocity is controlled as the mode of the cooling velocity of target from the first cooling collection The injection flow of the cooling medium of pipe 211a~211c injection.It should be noted that cooling velocity said here is according to each The beginning of cooling step and at the end of surface temperature and time for spending of each cooling step and value (each cooling step for calculating In average cooling rate), sometimes also include each cooling step in generate phase transformation fever caused by heating.

Table 5 show it is each under the conditions of cooling condition (cooling time (only initial stage cooling step), spray distance setting value and The real result value of cooling velocity) and distance controlling method.In the condition for being recorded as " relative position ", according to clamping element 23a, 23b, first cooling manifold 211a~211c, rail product size and measure and determine relative position in advance, make the first driving Portion 213a~213c driving, thus makes throw distance variation.In the condition for being recorded as " laser displacement gauge ", " eddy current type displacement meter " In, in position (the width direction center of each collector, length end) the setting laser displacement for the rangefinder 27 that Fig. 1 and Fig. 2 is recorded Meter or eddy current type displacement meter, carry out the measurement that the rangefinder 27 is adjusted the distance, and in the presence of errors with automatic at any time The mode that ground becomes defined spray distance drives first driving portion 213a~213c, is corrected.

[table 5]

It should be noted that the distance between the second cooling manifold 221 and rail 1, that is, the spray of the second cooling manifold 221 It penetrates distance and is set as 30mm, cooled down with not making throw distance variation.Moreover, the steel cooling using the second cooling manifold 221 The target cooling velocity of the foot 12 of rail 1 is set as 1.5 DEG C/sec.

Then, it is corrected using gaugger, produces the rail 1 as final product.At this point, final products The amount of warpage of up and down direction be every 25m of length direction be along the vertical direction the lower warpage of 50mm.

Also, it by carrying out choosing sample and cold saw is disconnected to manufactured rail 1, is carried out firmly about selected sample Degree measurement.As the method for Determination of Hardness, on the surface in the width direction center on the head of rail 1 11 and away from head 11 Surface is to have carried out Brinell hardness test at 5mm, 10mm, 15mm, 20mm and 25mm depth location.

As shown in table 5, each condition difference of the average value of Brinell hardness is HB3 hereinafter, smaller, but by embodiment 3-1's Spray distance be set as according to clamping element 23a, 23b, first cooling manifold 211a~211c, rail product size and the phase that determines To a side of the condition of position compared with automatically controlling the condition of spray distance of embodiment 3-2,3-3, found out from 21 samples The value of the standard deviation of hardness is big.The main reason for standard deviation as embodiment 3-1 increases, it is contemplated that cooling manifold is along long Degree direction configure in series it is multiple, caused by generating the variation of the measured value of respective relative position or the machine error of driving portion The situation of difference.

It is confirmed as a result, in order to control spray distance and is preferably able to measure the device of spray distance online, preferably set Set laser displacement gauge or eddy current type displacement meter etc..

In addition, in embodiment 3, the amount of warpage of product is larger, therefore make second in the driving by the second driving portion 223 Cooling velocity, the spray distance of cooling manifold 221 have also carried out heat treatment procedure under conditions of variation has occurred.At this point, by first The spray distance of second cooling manifold 221 of phase cooling step is set as 30mm, is 1.5 DEG C/sec by cooling velocity control, is entering At the time of final cooling step, the spray distance of the second cooling manifold 221 is set as 20mm, by cooling velocity be set as 2.5 DEG C/ Second, it is cooled down.As a result, the amount of warpage of the every 25m of rail becomes upper warpage 10mm, amount of warpage is reduced, and is successfully controlled Amount of warpage is made.

Label declaration

1 rail

11 heads

12 foots

13 web portions

2 cooling devices

21 first cooling ends

The first cooling manifold of 211a~211c

212a~212c the first adjustment portion

The first driving portion of 213a~213c

22 second cooling ends

221 second cooling manifolds

222 second adjustment portions

223 second driving portions

23a, 23b clamping element

Thermometer in 24 machines

25 trucking departments

26 control units

27 rangefinders

3 carrying-stations

4 move out platform

5 go out side thermometer.

Claims

1. a kind of cooling device of rail, by the head and foot's spray cooling medium of the rail to austenitic temperature region come Pressure cooling is carried out to the rail, wherein

The cooling device of the rail has:

First cooling end, has multiple first cooling manifolds and the first driving portion, and the multiple first cooling manifold is to the head The cooling medium of the crown side the Mian Jitou injection gas in portion, first driving portion is by making the multiple first cooling The first cooling manifold of at least one of collector is mobile and makes the spray distance for the cooling medium sprayed from first cooling manifold Variation；And

Second cooling end has the second cooling manifold that the cooling medium is sprayed to the foot.

2. the cooling device of rail according to claim 1, wherein

The cooling device of the rail is also equipped with:

Control unit adjusts the spray distance by controlling first driving portion；And

Thermometer in machine measures the surface temperature of the rail,

Control unit cooling velocity according to obtained from the measurement result as thermometer in the machine and preset mesh Cooling velocity is marked to adjust the spray distance.

3. the cooling device of rail according to claim 1 or 2, wherein

First cooling end is also equipped with the first adjustment portion, which makes from the injection of the multiple first cooling manifold The injection flow of the cooling medium changes.

4. the cooling device of rail described in any one of claim 1 to 3, wherein

Second cooling end also has the second driving portion, which is made and keeping second cooling manifold mobile The throw distance variation for the cooling medium sprayed from second cooling manifold.

5. the cooling device of rail according to any one of claims 1 to 4, wherein

Cooling manifold more than any one in first cooling manifold and second cooling manifold has for measuring The rangefinder of the spray distance,

The cooling device of the rail, which has, controls first driving portion and the second drive based on the value that the rangefinder is measured to The device of driving portion more than any one in dynamic portion.

6. a kind of manufacturing method of rail, wherein

By head from the rail to austenitic temperature region and foot spray cooling medium the rail is forced When cooling,

The cooling medium of gas is sprayed to the crown side Mian Jitou on the head from multiple first cooling manifolds,

The cooling medium is sprayed from the second cooling manifold to the foot,

Made and keeping the first cooling manifold of at least one of the multiple first cooling manifold mobile from the first cooling collection The throw distance variation of the cooling medium of pipe inspection.